English

Sharp comparison and maximum principles via horizontal normal mapping in the Heisenberg group

Analysis of PDEs 2016-02-15 v3

Abstract

In this paper we solve a problem raised by Guti\'errez and Montanari about comparison principles for HH-convex functions on subdomains of Heisenberg groups. Our approach is based on the notion of the sub-Riemannian horizontal normal mapping and uses degree theory for set-valued maps. The statement of the comparison principle combined with a Harnack inequality is applied to prove the Aleksandrov-type maximum principle, describing the correct boundary behavior of continuous HH-convex functions vanishing at the boundary of horizontally bounded subdomains of Heisenberg groups. This result answers a question by Garofalo and Tournier. The sharpness of our results are illustrated by examples.

Keywords

Cite

@article{arxiv.1305.5638,
  title  = {Sharp comparison and maximum principles via horizontal normal mapping in the Heisenberg group},
  author = {Zoltán M. Balogh and Andrea Calogero and Alexandru Kristály},
  journal= {arXiv preprint arXiv:1305.5638},
  year   = {2016}
}

Comments

Published in: J. Funct. Anal. 269 (2015), no. 9, 2669-2708

R2 v1 2026-06-22T00:21:50.578Z